Device for binding of pulp bales

ABSTRACT

A binding device for binding pulp bales  13  with wire  12  drawn from a wire magazine comprises a feed means  20  for feeding and tightening the wire, a guide means  14  for guiding the wire round the bale  13  during forward feeding thereof, means  17  for cutting the tightened wire and twisting together the ends thereof, and a take-up unit  34  for taking up the slack loop of wire  33  arising from the tightening of the wire. A spring-loaded device  30  adjacent to the feed means damps the jerk which occurs when the slack loop  33  of wire runs out and wire  12  begins to be drawn from the magazine.

FIELD OF THE INVENTION

[0001] The present invention relates to apparatus for binding pulp baleswith wire drawn from a wire magazine, preferably a reel of wire. Moreparticularly, the present invention relates to such apparatus includingmeans for feeding and tightening the wire, guide means for guiding thewire around the object (bale) during forward feeding, means for cuttingthe tightened wire and holding and twisting together the ends thereof,and a take-up unit for taking up the slack loop that arises when thewire is tightened.

BACKGROUND OF THE INVENTION

[0002] Pulp bales are bound by means of known devices of theaforementioned type, examples of such devices being disclosed in SwedishPatent Nos. 380,496; 509,532; and 509,534. As described in thesespecifications, the free end of the wire is fed forwards through thecutting and twisting means and is guided around the bale by guide means.When the wire end reaches the cutting and twisting means for the secondtime, feeding is stopped and the wire end is gripped and held. The guidemeans releases the wire and the feed means is reversed in order totighten the wire around the bale, whereafter the wire is cut and theends twisted to form a knot. The reverse fed wire is used in the nextbinding operation. Known devices have a high noise level and sufferfrequent breakdowns due to kinks and tangles in the wire.

[0003] It is one object of the present invention to improve thereliability and availability of such apparatus, as well as to reduce thenoise level, to reduce the risk of kinks and tangles in the wire, toreduce the mechanical stresses on the device, and to permit a high feedrate of the wire.

SUMMARY OF THE INVENTION

[0004] This and other objects have now been realized by the invention ofapparatus for binding bales with wire comprising feed means for feedingand tightening the wire, a guide for guiding the wire fed by the feedmeans around the bale, wire processing means for cutting, tightening andtwisting the ends of the wire, a take-up unit for taking up a slack loopin the wire created by the tightening of the wire, and spring-loadedfeed means disposed upstream of the feed means with respect to the balefor dampening motion in the wire upon taking up of the slack loop bycontinued feeding of the wire. Preferably, the apparatus of the presentinvention includes a wire magazine for supplying the wire to the feedmeans. Most preferably, the wire magazine comprises a reel of the wire.

[0005] In accordance with one embodiment of the apparatus of the presentinvention, the spring-loaded feed means is disposed between the feedmeans and the wire magazine. In a preferred embodiment, thespring-loaded feed means is disposed adjacent to the feed means.

[0006] The objects of the present invention are achieved by a resilientdevice disposed between the feed means and the wire magazine and closeto the feed magazine in order to dampen the jerk that occurs when theslack loop of wire runs out and wire starts to be drawn from themagazine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention may be more fully appreciated by referenceto the following detailed description which, in turn, refers to thedrawings, in which:

[0008]FIG. 1 is a top, elevational, partially cut away view of a bindingmachine according to the present invention, during forward feeding ofthe wire;

[0009]FIG. 2 is a top, elevational, partially cut away view of thebinding machine shown in FIG. 1 during tightening of the wire; and

[0010]FIG. 3 is a top, elevational, enlarged view of the feed unit ofthe binding machine shown in FIG. 1.

DETAILED DESCRIPTION

[0011] The binding device shown in the figures has a frame 10 supportinga number of units for different operations. A feed unit 11 is arrangedto feed binding wire, which is most commonly steel wire, 12, from a wiremagazine (not shown) in the form of a reel from which the wire isunwound. A wire guide means in the form of a rail 14 encircles the pulpbale 13 to be bound. The bale 13 is carried by a bale feed conveyor 15,16, in a direction perpendicular to the plane of the paper, into theguide rail 14. A binding unit 17 comprises means for cutting the wire,gripping the wire ends and twisting the wire ends. The binding unit isof conventional type and is not shown and described in detail, referencebeing made to the above-noted patent specifications.

[0012] The feed unit 11 is shown in the figures with a cover plateremoved and is shown enlarged in FIG. 3. It comprises a feed pulley 20driven by a reversible motor (not shown), and the wire 12 is compressedagainst the feed pulley by pressure rollers, 19, 21, and 22, in order toexert a frictional force on the wire. The wire passes around achange-of-direction pulley 23, by means of a guide pulley 24, aroundthree change-of-direction pulleys 25, 26, and 27, and a guide pulley 28,to a feed pulley 20. The three change-of-direction pulleys, 25 through27, are mounted upon a block 30 which slides on a guide pin 29 which isfixed relative to the frame, which block is pressed by means of a spring31 towards an outer end position, the wire tension being opposed to theforce of the spring. The force of the spring is appropriately adjustedso that under normal wire tension the block 30 is barely retained in itsouter end position. Inasmuch as the tension in the wire gives rise to aresultant force on the block 30 which is parallel to and coaxial, oralmost coaxial, with the guided motion of the block, no lateral forceswill be acting on the guided motion of the block.

[0013]FIG. 1 shows the binding device during forward feeding of the wireat a point when the feed pulley 20 has fed the free end 32 of the wire12 around the bale 13 and the end has been guided by the guide rail 14back to the binding unit 17. The binding unit 17 then grasps and holdsthe wire end 32. The wire guide rail 14 is axially split and opens atthis time, releasing the wire 12, and when the feed pulley 20 reversesdirection, the wire will be tightened around the bale 13 as shown inFIG. 2. When the wire 12 tightens as shown in FIG. 2 the reverse fedwire will form a slack loop 33 in an elongated wire take-up unit 34.When the wire 12 is tightened, the binding unit 17 will cut off the wireand twist the ends if to form a knot.

[0014] After a wire has been passed around the bale as described, thebale is moved a certain distance forward by the bale conveyor 15, 16 toreceive another lap of wire. The feed pulley 20 again begins feeding thewire end, and at first wire is taken from the slack loop 33 left by thepreceding reverse feed operation and the feed pulley 20 quickly attainsthe full feed rate which may be e.g. 4.5 m/s. When the slack runs outand the slack loop reaches the three change-of-direction pulleys, 25-27,mounted on the block 30, the wire will begin to be drawn from thechange-of-direction pulley 23 and the stationary wire will begin toaccelerate up to the feed rate. The jerk that occurs when the slack loopof wire reaches the change-of-direction pulleys, 25-27, will compressthe spring 31, thus damping the jerk in the stationary portion of thewire so that it can accelerate smoothly. The spring should not bepre-stressed and its progressivity should be such that there is time forthe force exerted by the wire to brake the return motion of the block sothat the block does not stop abruptly in its normal position, as thiscould cause a risk of kinking and tangling of the wire, even though themotion of the block 31 when the slack loop 33 of wire reaches the threechange-of-direction pulleys, 25-27, reduces the risk thereof. Thespring-loaded block 31 achieves a considerable reduction in the risk ofkinking and tangling of the wire and simultaneously reduces the stresson the feed pulley 20 and on its motor and gearbox if any, which mayresult in increased lifetime of these parts. Application of theinvention permits the use of a very high wire feed rate.

[0015] Although the invention herein has been described with referenceto particular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. a device for binding pulp bales (13) with wire (12) which is drawnfrom a wire magazine (9), preferably a reel of wire, comprising a feedmeans (20) for feeding and tightening the wire, a guide means (14) forguiding the wire round the bale (13) during the forward feeding thereof,means (17) for cutting the tightened wire and twisting together the endsthereof, and a take-up unit (34) for taking up the slack loop (33) ofwire arising from the tightening of the wire, which device ischaracterized by a spring-loaded means (30) between the feed means (20)and the wire magazine (9) and located close to the feed means in orderto damp the jerk that occurs when the slack loop of wire runs out andwire begins to be drawn from the magazine.